Hello,
There was a fog effect in our engine for a time ago but we didn't expose it until now.
We have revealed this feature in the beta version and we will promote it production after some testings.
You can play with it in the beta version:
www.gamemaker3d.com/editor/beta.html
You will see a few new parameters under Material, Terrain, and Water:
Enable Fog
Fog Color
Fog Min Distance
Fog Max Distance
In order to enable the fog in your scene, enable it for all the relevant materials.
If you have a terrain or water, you should enable the fog in them too.
About the performance, unless you have hardware acceleration, the distance should affect the performance that much.
In order to increase the performance, try the following steps:
1. Merge all the static primitives in your game using the Merge command
2. Use as fewer collisions and polygon collision as possible
3. Use as fewer water objects as possible
4. Build your own fake camera controller because the first person camera controller is very slow.
You can still use the Camera Controller without collision and add the code for the fake camera controller. Here is an example:
www.gamemaker3d.com/player?pid=016130
Regards,
Cyberix3D team